1. Field of the Invention
The present invention relates to a robot system constituted of a robot and peripheral devices, and more specifically relates to a robot system that increases the operating speed of a robot and improves the operation efficiency of the system by learning.
2. Description of Related Art
In production sites, production lines including a system, which is constituted of a robot and peripheral devices, have target cycle times. To achieve the target cycle times, teaching operators perform a teaching operation by trial and error using experience and know-how of the operators, such as devising the configuration of teaching programs to operate the robot or teaching convenient postures.
In this case, an operating speed is increased depending on techniques of the operators, thus deteriorating operating efficiency and requiring significant time. To solve this problem, a method for increasing the operating speed without depending on the techniques of the operators, by repetition of learning the same operation is proposed (for example, Japanese Unexamined Patent Publication (Kokai) No. 2011-167817, hereinafter referred to as “patent document 1”).
The invention described in patent document 1 requires an additional sensor to the robot for precise vibration suppression. Also, in the case of the operation in which the position and posture of a workpiece change in accordance with a state of the workpiece, the operation is difficult to learn in arbitrary positions.
In response to this problem, a method in which a virtual workpiece is disposed in arbitrary positions and operated to learn the operation in the arbitrary positions is known. However, since the workpiece is not actually present, this method cannot correctly learn a load applied to the robot and the like. Also, the operation may be learned even in unused positions, unless the virtual workpiece is disposed in consideration of a disposition state of the workpiece on an actual production line.